Chocolate extrusion printer is halfway to making s’mores

Chocolate has got to be one of the worst choices as a printing medium. It’s extremely fussy when it comes to melting point, and even in the right state the flow of the material is not going to play nicely with high-resolution designs. With this in mind, we applaud the progress the student team from Carnegie Mellon University has made with WonkaBot, their chocolate extrusion printer.

Unlike the syringe-based paste extruder from last month, this offering uses an auger to push chocolate through a heated printer head. They’re using it to print designs on graham crackers. We love the UI they came up with for the task. It uses a virtual graham cracker as a canvas on your laptop and allows you to use the touchpad or mouse to draw your design. That input is then converted to g-code and sent to the CNC machine for printing. See it in action after the break.

That said, ours is different in that you can literally throw in a chocolate bar and have it come out the other side. It is my understanding that the first printer you posted needs a specially formulated chocolate and the second requires the user to pre-melt the chocolate.

When I was doing my Due Dilligence I came upon a design in Britain that uses a very cute pair of orientable pipes. “my” design indeed included peltiers, though I never got to implement them. Oh well, once published anywhere, international patenting rights are lost anyway, so we might as well enjoy.

Find me in Facebook if you want to use the 3Dcho.co label, I am busy elsewhere for a while.

I’ve never found an author to say chocolate is non-newtonian, but then, it has behaved sort of that for me.

First, I can prove I was working with Kickstarter this idea for two months earlier this year, after quite a bit of experimentation last year, and registered and paid for that site a while ago.
Second, my intention was to have someone else use my website – check me out, I have solid credentials in open source, and the 15iLS is the first profit-making venture I am involved in a long time. Even then, we intend our stuff here to be open design, so, talking about doing the nasty to the wrong tree, we’re two of a kind here…

No ill will, Reb, I sure do have the same affection for squatters as you do, keep barkin’.

But don’t forget that because some datum comes from the Internet doesn’t make it true, you know!

no offense taken, and actually it should be I who apologises, as my implying there was a troll involved was gratuitous and unnecessary, though the line with the chocolate as troll fodder was too good to pass…

Have they considered adding a second nozzle to spray a coolant on the chixels (Chocolate Pixels), something like liquid nitrogen or supercooled air, it might improve the quality of the printing. Also do they need a taste tester? :)

So the original intent of the project was to do 3D (similar to the links to posted) but two things got in our way:

1) Time (as always)

2) It turns out Hershey’s chocolate isn’t tempered so it doesn’t “want” to harden after being melted. We didn’t have enough time to test other chocolates but I have a feeling a chocolate made for melting would work better.

Additionally, we wanted to use a Peltier unit for cooling but graham crackers don’t conduct heat very well :/

We briefly considered dipping the cracker into liquid nitrogen between layers to flash freeze the chocolate but decided against it as frozen graham crackers don’t taste very good.

How about a cooling stream? Have a jet of cold air follow the extruding tip and cool the chocolate from above. Not sure how you’d cool it enough, but first try might just be an extremely long length of tubing that passes through a cooler filled with ice, chilling the air.

Nice work though! Congrats on making hackaday! (One day I’ll get a project done that will make it up here… one day!)